package 面试;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

//自旋锁
public class SpinLockDemo {
    AtomicReference<Thread> atomicReference = new AtomicReference<>();

    public void myLock(){
        Thread thread = Thread.currentThread();
        System.out.println(Thread.currentThread().getName() + "\t进来！");
        while (!atomicReference.compareAndSet(null, thread)){

        }
        System.out.println(Thread.currentThread().getName() + "\t获取到锁！");
    }

    public void MyUnLock() {
        Thread thread = Thread.currentThread();
        atomicReference.compareAndSet(thread, null);
        System.out.println(Thread.currentThread().getName() + "\t释放锁！");
    }

    public static void main(String[] args) {
        SpinLockDemo spinLockDemo = new SpinLockDemo();
        new Thread(() -> {
            spinLockDemo.myLock();
            try {TimeUnit.SECONDS.sleep(5);} catch (InterruptedException e) {e.printStackTrace(); }
            spinLockDemo.MyUnLock();
        },"t1").start();

        try {TimeUnit.SECONDS.sleep(1);} catch (InterruptedException e) {e.printStackTrace(); }

        new Thread(() -> {
            spinLockDemo.myLock();
            spinLockDemo.MyUnLock();
        },"t2").start();
    }
}
